Manuka honey is a honey unique to New Zealand, derived from the nectar of the flowers of manuka (Leptospermum scoparium), which grows only in New Zealand, and is known to have strong antibacterial activity and other physiological functions. However, a kind of manuka honey (jelly bush honey) is also collected from a manuka relative (Leptospermum polygalifolium) growing in Australia.
With its strong antibacterial activity, it is thought that manuka honey may be able to eliminate Helicobacter pylori, a cause of stomach cancer. Physiological activities including this antibacterial activity are thought to vary considerably among different manuka honeys.
A “Unique Manuka Factor” (UMF) based on antibacterial activity converted to phenol activity is used as one index of the antibacterial activity and other bioactivity of manuka honey. It has been reported (Non Patent Literature 1,2) that an antibacterial constituent of manuka honey is an aldehyde called methylglyoxal (MGO) (see FIG. 9). Based on this report, the amount of MGO is sometimes used as an index of the bioactivity of manuka honey.
Manuka honey has also been reported to contain methyl syringate (MSYR) (shown below), and to have active enzyme elimination ability (Non Patent Literature 3) (see FIG. 9). Apart from manuka honey, this methyl syringate is also found in large quantities in asphodel honey obtained in Sardinia, Italy (Non Patent Literature 4). In addition, a glycoside of one sugar bound to methyl syringate has been isolated and identified from aniseed (Non Patent Literature 5).